conceiving

Hi so I need some advice. Ive been to my doctors to get an ultrasound and blood tests done and they can't find anything wrong so they say but I have irregular periods. To the point where sometimes I can bleed for 2 weeks straight or bleed for a week then not for two days then bleed again. I also had the rod (contraceptive) for 8 months which the entire time it was in my arm I had my period the ENTIRE time! Me and my partner of 2 years have been trying for 3 months and can't fall pregnant. It's not him as he already has a child from a previous relationship but it's really putting me down. What if I can't get pregnant? Is it possible that me having my period for 8 months straight could of affected my egg count?? :(